Print out the location of expanded multiclass defs in TableGen errors.

When reporting an error for a defm, we would previously only report the
location of the outer defm, which is not always where the error is.

Now we also print the location of the expanded multiclass defs:

lib/Target/X86/X86InstrSSE.td:2902:12: error: foo
  defm ADD : basic_sse12_fp_binop_s<0x58, "add", fadd, SSE_ALU_ITINS_S>,
             ^
lib/Target/X86/X86InstrSSE.td:2801:11: note: instantiated from multiclass
  defm PD : sse12_fp_packed<opc, !strconcat(OpcodeStr, "pd"), OpNode, VR128,
            ^
lib/Target/X86/X86InstrSSE.td:194:5: note: instantiated from multiclass
    def rm : PI<opc, MRMSrcMem, (outs RC:$dst), (ins RC:$src1, x86memop:$src2),
        ^

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162409 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/TableGen/TGParser.cpp b/lib/TableGen/TGParser.cpp
index b9c7ff6..5e2b66e 100644
--- a/lib/TableGen/TGParser.cpp
+++ b/lib/TableGen/TGParser.cpp
@@ -2277,7 +2277,10 @@
                      DefName, StringRecTy::get())->Fold(DefProto, &MC);
   }
 
-  Record *CurRec = new Record(DefName, DefmPrefixLoc, Records);
+  // Make a trail of SMLocs from the multiclass instantiations.
+  SmallVector<SMLoc, 4> Locs(1, DefmPrefixLoc);
+  Locs.append(DefProto->getLoc().begin(), DefProto->getLoc().end());
+  Record *CurRec = new Record(DefName, Locs, Records);
 
   SubClassReference Ref;
   Ref.RefLoc = DefmPrefixLoc;